With the aid of such an adjusting mechanism which is described in U.S. Pat. No. 3,747,947, the mass inertia of the ski is changed about a vertical axis which extends approximately in the binding area vertically through the surface of the ski, to thus give for example to a so-called compact ski of relatively short length the traveling characteristis of a long ski selectively when with the aid of the adjusting mechanism, the two mass members are shifted toward the tip or tail of the ski.
The purpose of the invention is to construct such an adjusting mechanism to provide a construction which is as simple as possible and thus inexpensive, the two mass members of which mechanism can be moved within the ski member to a desired location along the longitudinal axis of the ski and can be secured thereat, without creating the risk of a jamming of the mass members in the ski member due to the occurrence of twistings and bendings.
In an adjusting mechanism of the above-mentioned type this purpose is attained according to the invention by the belts or connecting elements comprising at least two flat belts which can be stressed for pull and pressure, the free ends of which flat belts can be connected to each one of the mass members, and by at least one first drum being connected to the set wheel, onto the circumference and from the circumference of which drum the flat belts can be wound and unwound.
By using flat belts as connecting elements, the two mass members can be pulled and also pushed into the respective desired position, because such flat belts can be stressed for both pull and also pressure. To adjust the mass members, the flat belts are wound onto and removed from a drum, and for each flat belt there can be provided a separate or, however, for both flat belts a common drum. If both flat belts are wound onto one single common drum according to a preferred embodiment, then they lie in every winding position one on top of the other and can during their unwinding from the drum, for example with the aid of suitably formed sliding guides, be moved one time in direction toward the tip of the ski and one time in direction toward the tail of the ski. These flat belts have thereby the same elastic characteristics as for example a flat belt which is used in a tape measure roll, which is advantageously manufactured of steel and is slightly arced in its transverse direction so that it has a greater stiffness in its longitudinal direction.
According to various embodiments and developments of the invention, it is possible to arrange in place of the single drum also two drums side-by-side, and in every case one drum is associated with a mass member and a flat belt. If both drums are provided with separate set wheels, then it is also possible to adjust the two mass members independently of one another in the respectively desired manner. On the other hand, it is possible to move with the two drums each of the two flat belts and two mass members, so that the adjusting mechanism has all together four mass members, which for example may be advisable when the mass members are guided in two guideways which extend parallel to one another, so that in the central longitudinal axis of the ski the guideways can be constructed through-going from top to bottom to create a greater rigidity than a ski which is provided with only a relatively wide guideway for the mass members.
According to a further development of the invention, the guideway for the mass members is formed by a hollow member made of fiber-reinforced plastic, which is to be manufactured by itself and independently from the actual ski member. Such a very flat and thin-walled elongated hollow member permits a very secure guiding of the flat belts, so that these can become only slightly wavy during a pressure stress for moving of the mass members, which can influence neither their movement nor the movement of the mass members. The mass members themselves are also guided in the flat hollow member so that it forms with same and the flat belts one structural unit. The one or several drums for moving the flat belts are to be arranged in a housing, which is to be connected through a moistureproof connection to the ski member or the hollow member, if the hollow member was earlier built into the ski member during the manufacture of the ski.
According to an important further development of the invention, a second drum is provided, onto which or from which a third flat belt can be wound and removed, and the rotary movements of both drums are coupled. This third flat belt is during the winding and unwinding of the two first flat belts also wound above these onto the first drum, which causes the wound-up first two flat belts to be pressed firmly against the circumference of the first drum, also in the case of several winding-up layers. Even during an unwinding of the two first flat belts from the first drum, a sudden unwinding of layers of the two first flat belts cannot occur, which could lead to a blocking of the adjusting mechanism.